/*
 * Copyright 2008 the original author Ang Gao.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *       http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 * ApplicationEventSource.java 2008-11-7
 */
package ie.ucc.cs.anggao.finalproject.client.support.event;

/**
 * Represents a source by which application events can be fired. As such, it
 * provides method to register application event listeners that will be notified
 * of the fired event.
 * 
 * @author GaoAng
 * 
 */
public interface ApplicationEventSource {

	/**
	 * Adds the given application event listener to this source.
	 * 
	 * @param listener
	 *            The application event listener that will notified of the events
	 *            fired by this source.
	 */
	void addListener(ApplicationEventListener listener);

	/**
	 * Removes the given application event listener from this source.
	 * 
	 * @param listener
	 *            The listener to be removed (if the given listener is not
	 *            registered with this source, this method will do nothing and
	 *            exit quietly).
	 */
	void removeListener(ApplicationEventListener listener);

	/**
	 * Removes all application event listeners registered with this source.
	 */
	void clearListeners();
}
